I'm unfamiliar with how the Android player sees the file system. Previously in Air apps I would create a directory in Documents to save my app's files in. What directory should I use for storage in an Android app?
As far as I know, the Blackberry emulator for Android apps copes perfectly fine with storing data to the external storage through Environment.getExternalStorageDirectory() and Environment.getExternalStoragePublicDirectory().
Note that these are both external storage. Usually you would just store data into the private data folder. You can find more information about the storage options on Android here.